In Coloassal Cave you start out next to a mill house, and you have to follow a gully down to the cave... there are secret passageways and dwarves that throw axes, and magical words in rooms (Xyzzy, Plugh, and Plover) :3

In HHGG, you start out in bed, its dark, and you go from there.. you really have to have some background knowledge of the series, tho, in order to figure out that you have to "lie down" or assemble the improbablilty drive :3